svn commit: r263424 - head/sys/arm/conf

[John-Mark Gurney]

Ian Lepore wrote this message on Sat, Mar 22, 2014 at 07:25 -0600:
> On Fri, 2014-03-21 at 12:04 -0700, John-Mark Gurney wrote:
> > Ian Lepore wrote this message on Fri, Mar 21, 2014 at 08:27 -0600:
> > > On Fri, 2014-03-21 at 09:43 +0000, Andrew Turner wrote:
> > > > On Thu, 20 Mar 2014 17:01:21 +0000 (UTC)
> > > > Ruslan Bukin <br at FreeBSD.org> wrote:
> > > > 
> > > > > Author: br
> > > > > Date: Thu Mar 20 17:01:21 2014
> > > > > New Revision: 263424
> > > > > URL: http://svnweb.freebsd.org/changeset/base/263424
> > > > > 
> > > > > Log:
> > > > >   Disable debugging by default.
> > > > 
> > > > I don't like this on head. I have found a number of issues that were
> > > > hidden because the kernel config most people were using for development
> > > > had WITNESS, INVARIANTS and DIAGNOSTIC disabled.
> > 
> > I agree...  HEAD needs these to make sure they are production ready...
> > 
> > > I disagree.  Witness is essentially useless anymore, because there are
> > > so many known LORs that nobody cares about when you report them that all
> > > it does is spews noise.  Maybe it's useful when you're looking for a
> > > particular problem, but leaving it on all the time has just lost its
> > > value.
> > 
> > I wouldn't be tracking down an AVILA bug if it wasn't for INVARIANTS..
> > 
> > Also, your complaint is solely about WITNESS not the other ones...
> > 
> > Considering how many people are writing new drivers for ARM, and might
> > be introducing locking issues w/ those new drivers, WITNESS should be
> > included, plus, if you disable INVARIANTS, it means that all the
> > lock assert functions will be turned off, and we might miss an odd
> > calling stack which doesn't hold a lock or something...
> > 
> > If you're using HEAD for performance, it's easy to turn these off..
> > 
> 
> My complaint is only about witness.

echo debug.witness.watch=0 >> /etc/sysctl.conf

:)  Not as fast as completely turning it off, but almost there..

> But... about being easy to turn off... how do they get turned off on
> non-head branches?  Does re@ really have to go grovel through 77 config
> files turning off diagnostic options?  Do we have to handle that
> difference when merging things to stable branches?

Apparently they do:
https://svnweb.freebsd.org/base?view=revision&revision=256283

Though, handling merging is an issue for all arches...  possibly more
anoying for ARM since it's so actively developed...

> Last time I tried to put something into arm/conf/DEFAULTS I got my hand
> slapped, but... putting the diagnostic options in there on head and not
> on stable branches would make the "touch 77 config files" problem go
> away.

Yes, I agree this is a problem and needs a solution, and I do agree
DEFAULTS would be a resonable place, but since there are others that
feel more strongly about what goes in DEFAULTS, they should speak about
it..

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."